I need to donate blood on Friday but my hemoglobin level was 11.5 on Monday. What can I do to increase my HG levels in 3 days, so I can donate?

Anemia evaluation. You are anemic and you should have a medical evaluation to determine the cause of your anemia: no quick 3 day cure- please get checked for the cause of your anemia: most common causes in women are iron deficiency and folic acid deficiency.